This invention relates to an improvement in the properties of dry powder complexes of zinc and manganese with methionine in the 1:1 ratio. In that sense it represents a significant improvement over the process disclosed in commonly owned U.S. Pat. No. 4,764,633, and as well, over commonly owned and now expired U.S. Pat. No. 3,941,818 issued Mar. 2, 1976 entitled "1:1 ZINC METHIONINE COMPLEXES", and U.S. Letters Pat. No. 3,950,372 issued Apr. 13, 1976, and entitled "1:1 MANGANESE ALPHA AMINO ACID COMPLEXES". Thus U.S. Pat. No. 3,941,818 and U.S. Pat. No. 3,950,372 relate to 1:1 complexed salts per se of zinc and manganese with the amino acid methionine. These salts, as identified in the earlier patents, have the useful feature of being highly body absorbable nutritional supplements for animals that provide readily available sources of zinc and manganese on the one hand, and the essential amino acid methionine on the other.
The common assignee of both of these patents makes a variety of transition metal complexes with alpha amino acids for sale. For example, see U.S. Pat. No. 5,061,815 relating to metal lysine complexes and methods for producing metal lysine complexes, as well as U.S. Pat. No. 5,278,329 for L-form 1:1 metal methionine complexes.
Complexes of lysine are very easily soluble in water. However, complexes of metals such as zinc and manganese and methionine are less soluble in water than the complexes of metals and lysine.
In Anderson, U.S. Pat. No. 4,764,633, an improvement in the complexing process is disclosed wherein the complexing of either zinc or manganese ions with methionine is conducted in the presence of a catalytically effective amount of ferric ion. The amount of ferric ion described is about 2% to about 10% based on the dry weight basis of the methionine, preferably from about 4% to about 8% based on the dry weight basis of the methionine.
For effective feed supplements, the supplement must be in a powdered, dry form, and it must be readily soluble in the gut of animals; otherwise, much of the supplement will not be absorbed into the blood stream. It also is useful to have water soluble supplements so that the user may administer them through aqueous systems.
While U.S. Pat. No. 4,764,633 enhances the amount of complexation, it does not enhance the solubility of the final dry product.
Accordingly, there has been a real and a continuing need for the discovery of a process which will enhance the solubility characteristics of the dry 1:1 complexes of zinc and manganese with methionine.
This invention has as its primary objective the fulfillment of this need in order that dry 1:1 manganese methionine complexes and dry 1:1 zinc methionine complexes have enhanced solubility in comparison with those prepared as described in U.S. Pat. No. 3,941,818 and U.S. Pat. No. 3,950,372.
For details of the desirability and the utility of 1:1 manganese methionine complexes, see the previously referred to U.S. Pat. No. 3,950,372 which is incorporated herein by reference. For details of the desirability and the utility of 1:1 zinc methionine complexes, see U.S. Pat. No. 3,941,818, which is incorporated herein by reference.
The method of accomplishing each of the above objectives of this invention will become apparent from the detailed description of the invention which follows hereinafter.